1. Field of the Invention
The invention relates to an extrusion head being suitable for homogenizing, mixing and heating/cooling of the material supplied from the extruder before it.
2. Description of the Prior Art
The toothed wheel of the present invention is driven for the adjustable shear effect and thus it can increase the mixing effect and the outlet temperature combined with a high shear speed and so it releases the vulcanization process. An extrusion head with shear effect to reach a predetermined temperature for elastomers is known and already in operation. A mixing effect cannot be achieved by this known extrusion head. The shear head technology is cost-intensive in that it is expensive to buy and has a relatively high energy consumption. Furthermore, some manufacturers in the plastics and rubber industry use such combinations of extruders with preflanged gear pumps in order to achieve a continuous final product with less pulsation. This process also does not provide a mixing process. Furthermore, German Patent publication DE3024552A1 shows a tangent system working with different circumferential speed and wiping blades in an open trough to discharge the material. German Patent Publication DE4114265A2 shows a toothed wheel system in a trough to melt plastic granulates or flakes being pressed out by the toothed wheel system to enable a filtering process.
German Patent Publication DE3426436A1 shows a combination of tangent systems working into each other.
The actual two-step pump design achieves a better heating of the material to be processed by the double crushing of material from the tooth gaps. This results in further savings at the following heating times.
The earlier described systems cannot produce a defined mixing process as well as not providing controllable friction heat.